They are by far the most heavily armed conventional strike platforms in the undersea battlespace. The U.S. Navy’s four Ohio Class cruise missile submarines (SSGNs) can carry a total of 154 Tomahawk Land Attack Cruise Missiles (TLAM Block-IV) in their missile silos. When added to the torpedo room, this gives a total of 176 full-size weapons. This quantity of weapons is already unparalleled, even by the latest Russian Navy SSGNs.
And the submarines may soon receive new hypersonic missiles which could transform their capabilities. The new missile, being developed under the Conventional Prompt Strike (CPS) program, will also reaffirm the U.S. Navy’s lead at a time when other navies are also rearming with hypersonic weapons.
The new missile will be able to hit targets with cruise-missiles like precision at extended ranges. And because of its incredible speed, greater than five times the speed of sound (Mach 5), it can do so within minutes of the target being identified. Its speed and maneuverability will also make it much harder to counter.
The U.S. Navy expect to deploy the new hypersonic weapon on Ohio-class SSGNs. The head of the Navy’s Strategic Systems Programs, Vice Admiral Johnny Wolfe, recently said that submarines will get the hypersonic strike weapon by 2025.
It will employ the Common Hypersonic Glide Body (CHGB) which is the same design as the U.S. Army will use. This will be married to a booster which can fit within the Ohio Class’ vertical launch tubes. These tubes are left over from when the submarines performed nuclear deterrence patrols with the Trident missile. Each of the massive silos can carry seven Tomahawk cruise missiles.
It is currently unclear how many of the new missiles will fit in each silo, but a reasonable assumption at this stage is two to three. Provided all 22 tubes currently used for missiles are able to accept the weapon, this would give a maximum load of 44 or 66 missiles. The Tomahawk will still remain relevant, maybe preferable in many scenarios, so a mixed load is likely to be carried. So the new missiles will not increase the number of weapons, but they do increase the potency and versatility.
Russia is also developing hypersonic missiles for its submarines. The new 3M22 Zircon missile (also Romanized Tsirkon) is an anti-ship weapon which fits into the same space as a cruise missile. The Mach 8 missile will equip the Pr. 855M Severodvinsk-II Class submarines and possibly upgraded Oscar-II class boats. Maximum weapons loads would be 32 and 72 respectively. There are indications that the test program for Zircon has suffered some complications but a November 30 test launch from a surface warship was reportedly successful.
China’s plans for submarine launched hypersonic weapons are less clear. They already have ground-based and air-launched weapons, and a version for surface ships is expected. It has to be considered within the Chinese Navy’s (PLAN) capacity to develop submarine launched versions if they make it a priority.
The Navy version of the CPS missile is likely to find itself onto the enlarged Virginia Block-V submarines and surface ships. But thanks to their incredible missile payload the Ohios will remain a major platform until they are retired. The new generation of weapon will greatly increase the tactical and strategic options available to U.S. commanders.